Influence of the 20-week anomaly scan on prenatal diagnosis and management of fetal facial clefts

Abstract

Objective: To investigate trends in prenatal diagnosis and termination of pregnancy rates in cases of fetal cleft lip with or without cleft palate (CL ± P), before and after the introduction in The Netherlands of the 20-week anomaly scan in 2007, and to assess the accuracy of this scan for the diagnosis of facial clefts.

Methods: This was a retrospective cohort study of consecutive cases of CL ± P diagnosed in 2001-2010 in the referral region of the Academic Medical Centre. Cases diagnosed prenatally were identified from the hospital's database. These data, grouped according to the periods before and after the introduction of the routine 20-week anomaly scan, were compared with data of all cases managed by the multidisciplinary cleft team, which services the same region, to identify cases of CL ± P that were not seen prenatally.

Results: We identified 123 cases of CL ± P diagnosed prenatally, of which 76% (93/123) were diagnosed before 24 weeks. In one case, the CL ± P was not confirmed after birth. There were 46 cases with associated structural anomalies and 76 isolated cases. The median gestational age at diagnosis decreased by 2 weeks after 2007 (P = 0.02). The proportion of isolated clefts detected prenatally increased significantly after 2007 (P < 0.0001), whereas the proportion of associated clefts remained stable over the years (P = 0.426). The overall detection rate of CL ± P increased from 43% before 2007 to 86% after 2007 (P < 0.0001), without an increase in terminations of pregnancy.

Conclusion: Introduction of the routine fetal anomaly scan has decreased the gestational age at diagnosis of CL ± P and has increased the proportion diagnosed prenatally, without a significant change in the number of terminations of pregnancy.

Keywords: 20-week anomaly scan; facial clefting; prenatal diagnosis; screening; ultrasound.